Dressing device for grinding wheels



Sept. 3, 1957 DRE Filed Dec. 29, 1954 n l 2 t ss/ 44 g C. A. COUP SSINGDEVICE FOR GRINDING WHEELS 2 Sheets-Sheet l 4J. l J

Sept. 3, 1957 c. A. COUP 2,804,868

DRESSING DEVICE FOR GRINDING WHEELS Filed Dec. 29, 1954 l 2 Sheets-Sheet2 INVEN TOR. CLARENCE A. COUP DRESSING DEVICE FOR GRINDING WHEELSClarence A. Coup, Meadville, Pa.

Application December 29, 1954, Serial No. 47 8,265

9 Claims. (Cl. 12S-11) My invention relates to dressing devices forgrinding wheels of abrasive material.

An object of my invention is to provide a proper support for thedressing tool, such as a diamond point, used in dressingvor forming thecontour of a grinding wheel of abrasive material.

Another object is the provision of an improved device for supporting thedressing tool in proper position relative to a grinding wheel to bedressed.

Another object is an arrangement in a supporting device for a tool whichprovides for ready visual inspection of the tool at its position fordressing a grinding wheel.

Another object is to provide a line of sight through a support to permitthe dressing tool to be properly observed during its positioningrelative to a grinding wheel.

Another object is the provision for accurately aligning and positioninga dressing tool carried by a support. l

Another object is the provision for accurate positioning and movement ofa dressing tool relative to a grinding wheel.

Another object is to provide an arrangement-for a minimum of partsproviding a maximum of tlexibility in the operation of the device. Y

Another object is to provide precision and universal manipulation in theuse of a dressing tool.

Another object is to provide results heretofore not obtainable and in anew and beneficial manner.

Other objects and a fuller understanding of my invenF tion may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawings, in which:

Figure l is a side elevational view of a device embodying my inventionwith portions cut away in section;

Figure 2 is a top plan view of my device as shown in Figure l;

Figure 3 is an end view of my device looking in the direction of thearrows 3 3 of Figure l;

Figure 4 is an enlarged sectional view taken through the line 4--4 ofFigure 1;

Figure 5 is a perspective view of the left-hand or free end of thetool-carrying arm of my device;

Figure 6 is a cross-sectional View of my device looking in the directionof the arrows 6 6 of Figure 1;

Figure 7 is a view somewhat like that of Figure 6 but showing thetool-carrying arm swung at an angle to its horizontal position shown inFigure 6 and illustrates another dressing operation in the use of mydevice; and

Figure 8 is a view also somewhat similar to the view of Figure 6 butshowing the tool-carrying arm disposed at an angle to its horizontalposition of Figure 6 and illustrates still another dressing operationwhich may be performed with my device.

As is well known, grinding wheels of abrasive material must beperiodically dressed or formed along their outer peripheral portion sothat the grinding wheel presents the proper profile for a grindingoperation. This dressing or forming of the grinding wheel is performedby the use of a tool, usually a piece of diamond referred toas a2,804,868 Patented Sept. 3, 1957 "ice diamond point, which must beproperly held in position relative to the grinding wheel during thedressing operation. My device is adapted to perform a number ofdifferent operations and variations in dressing a grinding wheel andalso provides for accuracy and ease in manipulation.

With reference to the views of the drawings, my device embodies asupporting member 12 which is bolted or otherwise secured to asupporting structure 11. The supporting structure 11 may appropriatelybe a magnetic chuck for magnetically holding the supporting member 12securely in position. The upper portion of the supporting member 12consists of a yoke or top portion 13 which is secured to the lowerportion of the supporting member by four bolts 14. The upper portion ofthe supporting member 12 and the yoke 13 together dene or form acylindrical bore or opening extending horizontally therethrough. v

A rotatable sleeve member 15 of an outside diameter complementing theinner `diameter of the bore extending through the supporting member ispositioned in the bore to extend from its opposite ends. The lit of therotatable sleeve member 15 in the supporting member isr such as topermit rotation of the sleeve member 15 while ac curately maintainingits alignment in a straight horizontal direction. Secured to the rearend of the sleeve member 15, that is, at the right-hand end shown yinFigures l and 2, is an annular end piece 16. This annular end piece issecurely engaged to the sleeve member 15 by set screws 22. The annularend piece 16 is thus secured to the sleeve member 15 so that the annularend piece and sleeve rotate together as though integral. The outer rearend of the end piece 16 `is knurledas at 17 to provide a convenienthand-engaging portion which may be seized by hand to rotate the endpiece 16 and all parts rotatable therewith. The end piece 16 also has anopening extending therethrough concentric with the open bore 28 whichextends through the sleeve member 15. The rear end of the end piece 16is champfered to form a sloping end face 23.

The annular end piece 16 has an annular groove 18 extending therearound.This groove l18 is wider at its bottom than it is at its .outer opening,the side walls thereof being at an incline to each other so as toconverge as the side walls extend radially outward of the end piece.Positioned in the groove 18 are a pair of wedge blocks 20. These wedgeblocks 20 each have opposed sloping Walls which complement the inclinedside walls of the groove 18. Each wedge block 20 has a threaded bolt 21extending therethrough in a radial direction. Ulpon tightening of athreaded bolt 21 so as to bear hard against the bottom wall of thegroove 18, the respective wedge block carried thereby is wedginglyforced up in tight engagement with the inclined side walls of theVgroove 18. By such tightening of the bolt 21, a wedge block 20 may belocked in a predetermined position around the circumferential extent ofthe groove 18.

To allow for the insertion of the wedge blocks 20 in the groove 18,there is provided in the end piece 16 a radially extending slot 19having Ia cross-section slightly larger than the maximum .cross-sectionof each block 20. As better shown in Figure 4, this slot 19 permits thewedge blocks 20 to be moved radially outward through the slot 19 intothe groove 18 prior to the mounting of the end piece 16 on the sleevemember 15. In Figure 4, which shows the parts enlarged, the variablepositioning of the wedge blocks 20 in the groove 18 is illustrated.

A xed stop finger 24 is mounted to the top of the yoke 13 adjacent theend piece 16. The stop linger 24 is acoommodated in a recess 46 and itis secured to the part 13 by a bolt 2S. As seen in Figures l, 2 and 4,the fixed stop linger 24 at its rearward end extends down some- 3 whatinto the groove 18. By this arrangement, the fixed stop iinger 24provides a reference and the wedge blocks 20 provide variable limits. Byadjustment of the position of the wedge blocks 20 in the groove 18 ofthe -end There is provided in a threaded opening in the yoke L13' athreaded bolt 26 so arranged that its rinner end may about the outersurface of the sleeve 15. A knurled head'- 27 on the threaded bolt 26permits the manual turning of the bolt 26 so as to tighten or loosen thebolt 26 and thus to er1-gage or disengage the sleeve 15. Upon looseningo'f the bo1t26, the sleeve 15 of the parts carried thereby may rotate inthe bore 'of the supporting member. `Upon tightening of the bolt 26, thesleeve 15 may be held in any determined rotational position.

It is to be noted that my device has a clear line of sight extendingthrough the rotational sleeve member 15 and the end piece 16 securedthereto. This line of sight extends along the axis of rotation of thesleeve member 15. The inner wall of the bore `28 is concentric with thisaxis of rotation.

A tool-carrying arm 31 extends forwardly from the support member 12.This tool-carrying arm 31 has an upright angle portion 32 which has abore registering with the horizontal bore through the support member andwhich also accommodates the sleeve member 15. The angle portion 32 ofthe tool-carrying arm 31 islirmly secured by brazing or other suitablesecuring means to the forward end of the sleeve member 15 so that theangle portion 32 revolves with the sleeve member 15 as though integraltherewith.

Preferably I provide a magnifying lens 29 at the forward end of thesleeve member 1S, the axis of the lens coinciding with the axis ofrotation of the sleeve member. This magnifying lens 29 is alignedtherefore on the line of sight through the device and provides formagnification of the object viewed through the line of sight from therear end of the device, that is, from adjacent the end piece 16. A snapring 49 or other suitable means is provided for retaining the magnifyinglens 29 in position.

At the free end of the tool-carrying arm 31, that is, Vat the left-handendvof the views of Figures l and 2, a crossslide member 33 is provided.The forward end face of the tool-carrying arm 31 and the rearwardopposed face of the slide member 33 are so milled or formed as tohaveangled opposing surfaces 34. The angle of the opposed surfaces 34 isapproximately 45 degrees fromthe horizontal plane when the parts are inthe position shown in Figures l and 2. The interiit and engagement vofthel slide member 33 and arm member 31 is such that the slide member 33may be accurately but freely moved transversely across the longitudinalaxis of the tool arm 31.

To secure the slide Vmember 33 inrinterlocked arrangement with the toolarm 31, there is provided a retaining plate 35 secured by bolts 36 tothe tool-carrying arm 31 as better illustrated in Figure 5. This plate35 overlays the slide member 33 in such manner as to permit the slidingmovement of the member 33 while holding the parts in interengagement.There is a vertically disposed groove in the forward end of thehorizontally disposed slide member 33 and positioned in this verticalgroove is a toolholding post 37. A screw bolt 38 extending through ahole in the tool-holding post 37 secures the tool-holding post 37 to theslide'member 33 and at a xed position relative thereto. To provide forvariation in the position of the tool-holding post relative to thetransverse slide member '33, there are a plurality of openings, ve

openings being shown, to permit the screw bolt 38 to be placed in anyone of the desired openings. The screw bolt extends through a selectedone of the ive selectable openings in post 37 in non-threaded engagementwith post 37 and extends in threaded engagement with a complementarythreaded opening in slide member 33. Thus, the elevation of the toolholding .post 37 may be adjusted relative to the transverse slide member33.

A diamond point or piece 40 is secured to and carried by adiamond-carrying member 39 inthe usual manner. This diamond point 40 onthe diamond-carrying member 39 provides a tool for cutting in theabrasive material of a grinding wheel and thus for the dressing of agrinding wheel. The diamond-carrying member 39 is secured in an openingin the top end of the tool-holding post 37 by a screw bolt 41. Worndiamond tools may be replaced on the post 37 by loosening of the screwbolt 41 and replacement of the worin tool comprised ofthe diamond point40 on its carrying member 39.

To 'providel'ir'nits to the transverse movement of the slide member 33relative to the arm 31, lthere are provided stop l'a'tehe's 42 which arefpiv'o'tally carried by screw bolts 43 on the opposite sides of the arm31. By swinging of one of the two stop latches 42 inl a horizontalposition, such as -shown in Figure 1, a stop is provided for transversesliding movement of the slide member v33 upon the abutment of the slidemember against the horizontally arranged stop latch 42. A stop latch 42may be swing in a vertical position out of the path of the slide member33 so as 'to permit 'movement ofthe slide member 33 without limit onthatside of the arm 31. By having stop latches 42011 the opposite sides ofthe arm y31, limits may' be selectably provided 'for transverse movementof the slide member 33 in a vdesired direction.

There fare also ,provided swin'gabl'e end plates 44 which are'pvotalysecured to the opposite ends of the transverse slide member 33, theseend plates 44 being pivotally carried bvs'crew bolts 45 secured to theopposite ends of the slide member 33. These end plates 44 'may be swungforwardly in a generally horizontal position to provide hand-'engaging'means'for 'the operator moving the slide member 33 in'a transverse'path.Also as desired, the end plates 44 may be 'swung to the horizontalposition shown in Figure "l' Vaidin this position the slide member 33 islocked in position by the abutment of the end plate 44 against the sideof the ann 3'1.

Y To provide for the setting 'of the tool-carrying arm 31 at apredetermined and desired position, there are provided markedcalibrations 47 'on .the top surface of the angle 'portion 32 "of thearm 31, and there are also provided calibrations 48 marked on the uppersurface of the yoke 13 of the support member 12. By adjust mentof thelinejsof thecalibrations 47 with reference to the lines of thecalibrations 48, the device may be adjusted to holdthetool-carrying armata desired angularity and the parts may be locked in the selectedposition by tightening of thebolt .'26 aganstthe surfacejof the sleevemember 15. if it is desired vto have the tool-carrying arm readily'revolve'relative to the axis of rotation of the sleeve member 15,- thebolt "26 is loosened and the tool-carrying arm'rnay be manually revolvedaround this axis. l

It is seen-from the views of the drawings, and particularly in Figures1, 2', and 3, that the operator using my device`A may pror'nrlyVposition the diamond point 40 relative tothe 4grinding 'wheel k30hylooking through the open bore of my device along the axis of rotation.The operator would look from right to left in Figure 1 from adjacent theopen end of the end piece 16 and look toward the diamond point 40through the magnifying lens 29. The arrangement permits the accuratepositioning ofthe dressing tool 40 and permits a good visualinspection'from an advantageous point' at all times during theoperation. Theeld of vision is sufliciently large to permit observation4of the diamondpoint, Y constituting the dressing tool, in a variety ofits positions, as for example, the various positions shown in Figures 6,7 and 8. As seen in Figure 3, the line of sight is clear by reason ofthe opening through the device along its axis and the magnifying lens 29provides the advantage of magnication, as well as the clear view alongthe line of sight.

To illustrate some of the operations that may be readily performed withmy device, I show in Figure 6 that by rotation of the arm 31 from itshorizontal position shown in full lines to an inclined position shown inbroken lines, a desired radius may be formed on the peripheral surfaceof a grinding wheel, such as grinding Wheel 30. In shaping such a radiuson the grinding wheel 30, the diamond point 40 is positioned below theaxis of rotation of the device. In Figure 6, the axis of rotation wouldcoincide with the point of intersection of the vertical and horizontallines'shown extending through the grinding wheel 30.

In Figure 7, there is illustrated the operation of providing aperipheral surface on the grinding wheel 30 which is at an angle forpart of the thickness of the grinding wheel 30 and which is alsoprovided with a stepped portion adjacent one side of the grinding wheel.The angular dressing of the grinding wheel 30 is provided by motion ofthe slide member 33 and the diamond point 40 carried therebytransversely of the arm 31, while the arm 31 is locked in the angularposition shown. This movement of the slide member 33 moves the diamondpoint in the desired angular path. By adjustrnent of the position of thetool-holding post 37 relative to the slide member 33 so as to move thediamond point toward the center of the grinding wheel 30, and thereafterby motion of the slide member 33 in the same angular direction, thedesired step formation in the grinding wheel may be obtained.

Another operation that may be performed with my device is illustrated inFigure 8, in which a concave or depressed surface is provided in theperipheral portion of the grinding wheel 30. In this operation, thetool-holding post 37 is adjusted so as to move the diamond point 40upwardly away from the arm 31 and beyond the axis of rotation of thedevice. In Figure 8, the axis of rotation coincides wtih the pointformed by the intersecting lines, of which one line extends radially ofthe grinding wheel 30 and the other line at right angles thereto extendsthrough the tool-holding post 37. With the diamond point in thisextended position, the arm 31 is revolved around the axis of rotationfrom the position shown in full lines to the position shown in brokenlines and back again in that reciprocating movement. This movement ofthe diamond point 40 against the grinding wheel 30 forms the contourshown in Figure 8.

The above operations are given only by way of example of some of themany operations that may be performed with my device. It is seen thatcompound movements may be readily obtained with a maximum of accuracyand with facility in performing the operation.

It has been found in practice that my device, although simple andeconomical in construction, provides superior results and performs aplurality of operations in an efiicient manner.

The present disclosure includes that contained in the appended claims,as well as that in the foregoing description.

Although this invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and scope of the invention as hereinafterclaimed.

What is claimed is:

1. A grinding wheel-dressing device comprising the combination of asupporting member, said supporting member having a bore extendingtherethrough, a sleeve member mounted on said supporting member andcoaxially with said bore, said sleeve member being adapted to 'berotated on the common axis of the said bore and sleeve member, saidsleeve member extending from opposite ends of the bore of saidsupporting member and having a straight opening extending therethroughfrom end to end along said axis to provide a line of sight through thesleeve member, a tool-carrying arm carried by the sleeve member at oneend of the sleeve member to revolve therewith and oif-set to one sideonly of the said common axis to continue said line of sight withoutobstruction by said tool-carrying arm, an annular handengaging membercircumferentially arranged around said sleeve member adjacent the otherend of the sleeve member and secured thereto for the rotation of thesleeve member and tool-carrying arm carried thereby on said common axis,said annular member having an annular groove arranged around theperiphery thereof, a pair of wedge blocks adjustably positioned in saidgroove, a finger-like stop member secured to said supporting memberadjacent said annular member, said linger-like stop member having aportion which projects into said annular groove and which co-operateswith the wedge blocks therein to limit the rotation of said sleevemember to a predetermined arc, a slide member slidably carried at thefree end of said tool-carrying arm at a location spaced fro-m said axisand movable at said free end in a path tangential to a circle generatedabout said axis, a tool mounting-post carried by said slide member forextending a dressing tool to a location proximate to said line of sight,and means for adjustably securing the sleeve member in xed rotativeposition relative to said supporting member.

2. A grinding wheel-dressing device comprising the combination of asupporting member, a rotatable member rotatably carried by saidsupporting member, said rotatable member having an opening extendingtherethrough along the axis of rotation of said rotatable member toprovide an open line of sight along said axis, toolmounting meanscarried by said rotatable member adjacent one end of said rotatablemember to hold a tool in dressing position, said tool-mounting meansbeing movable with said rotatable member to swing in an arc on saidaxis, said tool-mounting means extending radially away from said axis,thence forwardly away from said supporting member substantially parallelto said axis to a forward free end, and thence toward said axis, saidtool-mounting means, including slide means at said forward free end foreffecting a dressing movement of a dressing tool along a path tangentialto a circle generated on said axis, said open line of sight providingfor inspection from the other end of said rotatable member of saiddressing tool carried by said tool-mounting means in dressing position,an annular hand-engaging member carried by said rotative member forrotating said rotative member on said `axis to move said toolmountingmeans relative to said axis, said annular member having an annulargroove arranged around the periphery thereof, a pair of wedge blocksadjustably positioned in said groove, a finger-like stop member securedto said supporting member adjacent said annular member, said finger-likestop member having a portion which projects into said annular groove andwhich cooperates with the wedge blocks therein to limit the rotation ofVsaid rotatable `member to a predetermined arc, and locking meanscarried by the supporting member for locking said rotative member in aselected position of a plurality of selectable positions of the rotativemember relative to the supporting member.

3. A device for holding a grinding wheel-dressing tool in positioncomprising in combination support means, rotative means rotatablycarried by said support means, said rotative means being opentherethrough along the 7 axis Aof said rotative member to "provide aline :of sight along said axis 'from one side to the other side of saidsupport means, tool-'carrying means carried by said 'Ifotative meansadjacent one end thereof and which is adapted to move therewith `in an'arc about said axis and off-set from said axis to revolve with therotative means relative to said axis, said tool-carrying means includingtool-engagir'rgA 'means adapted to vhold a dressing tool in dressingposition along s'a'id line of sight, said tool-carrying mea'ns beingarranged to hold said tool-engaging means at a spaced axial distancefrom said rotative means to accommodate a grinding wheel along said lineof sight in advance of said rotative means and being arranged to oneside of saidv axis to maintain unobstructed said line of sight betweensaid rotative means and a dressing ltool engaged by said tool-engagingmeans, said tool-carrying meansrhaving inter-sliding portionspermitt'ing movement of said tool-'engaging means at said spaced axialdistance tangentially of a Vcircle generated on said axis, an annularmember carried 'by said rotative means and secured thereto adjacent theopposite end thereof and which is adapted to rotate therewith, saidannular member having 'an annular groove arranged around theperipherythereo'f, a pair of wedge blocks adjustably positioned in saidgroove, a finger-like stop member secured to said supporting memberadjacent said annular member, Said finger-like stop member havingaportion which projects into said annular groove and which co-operateswith the wedge blocks therein to limit the rotation of said rotativemeans to a predetermined arc, and locking means for securing saidrotative means in a selected 'fixed rotative position relative `to saidsupport means to hold said tool-carrying means at a selected directionfrom said axis.

4. The combination of a supporting member having a cylindrical boreextending therethrough, a cylindrical member in said bore and extendingfrom opposite ends thereof, said cylindrical member being reciprocal inan are about `the axis of said bore, said cylindrical member being openalong said axis to provide a line of sight therethrough from adjacentthe rearward end thereof, a magnifying glass carried by saidcylindrical` member adjacent the forward `end thereof and positionedathwart said axis to provide a magnified view along said line of sight,a toolcarrying arm carried by said cylindrical member at the forward endthereof and off-set from said axis, said tool-carrying arm being adaptedto swing with said cylindrical member on said axis, said tool-carryingarm having a free end extending1 forwardly from 'said cylindricalmember, and adjustable toolemounting means carried by the free .end ofsaid tool-carrying arm, said tool-carrying arm holding saidtool-mounting means at a spaced axial distance from the forward end ofsaid cylindrical member to accommodate a grinding wheel being dressed bya said tool along said line o f slight, said tool-mounting means beingadapted to hold a wheeldressing tool at variable positions relative tosaid axis, said tool-mounting means and tool-carrying arm beinginterconnected to permit adjustment of a said wheeldressing tool toselected positions along lines disposed at right angles to each other ina plane normal to said axis an annular member secured to saidcylindrical member adjacent one end thereof and which is adapted torotate therewith, said annular member having an annular groove arrangedaround the periphery thereof, a pair 'of wedge blocks adjustablypositioned in said groove, a finger-like Vstop 'member secured to saidsupporting member adjacent said annular member, said n'ger-like stopmember having a portion which propects into said annular groove andwhich cooperates with the wedge blocks therein to limit the rotation ofsaid sleeve member to a predetermined arc. Y

5. A dressing tool supporting device comprising a rotatable cylinder,said cylinder `having 'an opening 'extending therethrough along its-axis to provide 'a line lof 8 s'ightlthr'ough ztheeylinder along Isaidaxis, an arm carried by said cylinder to rotate `therewith -having aforwardly extending portion offset from said axis, a cross-slide carriedlby the free end of s'aid arm, said cross-slide being adapted to slide'transversely of said arm, and a tool-supporting member'earried by saidcross-slide and disposed at fight angles thereto, said tool supportingmember being adapted to support a dressing tool in position for dressinga grinding wheel and along said line 'of Sight, said crosss'lide andtuoi-supporting member being spaced an axial distance from the forwardend l'of said rotatable cylinder and a radial distance from said axis toaccommodate a said grinding wheel within said line of sight between saidrotatable `cylinderand :a tool held by the toolsupporti'ng memberwithout 'obstruction of said line of sight between a said tool and theforward end of the rotatable member an annular member carried by saidrotatable cylinder, said annular member having an anular groove arrangedaround the periphery thereof, Va pair of wedge blocks adjustablypositioned `in said groove, a finger-like stop member secured to saidsupporting member adjacent said annular member, said fmger-like stopmember having a portion which projects into said annular groove andwhich cooperates with the wedge blocks therein to limit the rotation yofsaid rotatable cylinder to a predetermined arc.

6. A device for holding a dressing tool during dressing of a grindingwheel comprising in combination a toolcarrying arm having itslongitudinal axis arranged parallel to, and `spaced from, a rotationalaxis about which said tool-carrying arm is reciprocably swingablc, aslide member being interlocke'd with said arm and slidably movabletransversely of the longitudinal axis of said arm, a post member carriedby said slide member at right angles thereto, said post member beingadapted to hold a dressing tool for said dressing operation, means foradjusting the position of said post member relative to said slide memberfor varying the distance of the dressing tool carried thereby from Vsaidlongitudinal axis lof said arm, a supporting member having Van openingextending therethrough along said axis, and a tubular member extendingthrough said opening in the supporting member and `having its forwardand rearward ends protruding from opposite ends thereof, saidtubular'member being open from end to end thereof along said axis toprovide a line of sight therethrough, said tool-carrying arm having aradially extending portion embracing and carried by the said tubularAmenbei' at the forward end thereof to hold the tool-carrying arm, thesaid tool-'carrying arm spacing the said post member from said tubularmember along said line `of sight to accommodate a said grinding wheelbeing dressed -forwardly of said tubular member an vannular' membercarried by said tubular member, said annular member having an annulargroove arranged around the periphery thereof, 'a pair of wedge blocksadjustably positioned in 'said groove, a finger-like stop member securedto said supporting member adjacent said annular member, said 1ingerlikestop member having a portion which projects into said annular groove andwhich `cooperates with the wedge blocks therein to limit the rotat-ionof said tubular member to a predetermined arc.

7. A device for dressing a grinding wheel, comprising a support, aVsleeve revolvably mounted to said support, said sleeve being open from`end to end along its axis of rotation to lprovide a line of sighttherethrough along said axis, magnifying means positioned in said sleeveto provide magnification of said sight, an arm carried by the forwardend of said sleeve to revolve therewith, said arm having `a radiallyextending portion secured to said sleeve and a longitudinally extendingportion extending forwardly from said sleeve parallel to said axis, saidlongitudinally extending portion having at its forward free end a slidesurface disposed transversely of the said longitudinallyextendingportion, a slide member in vsliding engagement with said slide surfaceand movable laterally of said longitudinally extending portion,adjustable stop means for providing limits to the sliding movement ofsaid slide member, and a tool-holding post carried by said slide memberat selectable extensions of the post relative to said slide member, saidtool-holding post being adapted to hold a dressing tool adjacent theforward end of said arm along said axis and in said line of sight anannular member carried by said sleeve, said annular member having anannular groove arranged around the periphery thereof, a pair of wedgeblocks adjustably positioned in said groove, a ringer-like stop membersecured to said supporting member adjacent said annular member, saidnger-like stop member having a portion which projects into said annulargroove and which co-operates with the wedge blocks therein to limit therotation of said sleeve to a predetermined arc.

8. In a dressing device for dressing grinding wheels, a tool-carryingarm revolvable about an axis and carried by a support at its rearwardend, said arm having a slideway provided on the forward face of its freeend spaced from said support, a slide member in sliding engagement withsaid slideway and arranged to move in a line of travel transverse ofsaid arm and in a plane at right angles to said axis, a tool-holdingpost secured to said slide member and disposed at right angles to saidline of travel, and securing means for securing said post member atselected of variable extended positions relative to said slide member,said tool-holding means being adapted to hold a dressing tool adjacentthe free end of said arm and directed annular groove and whichco-operates with the wedge to said tool-carrying arm, said annularmember having an annular groove arranged around the periphery thereof, apair of Wedge blocks adjustably positioned in said groove, a finger-likestop member secured to said supporting member adjacent said annularmember, said finger-like stop member having a portion which projectsinto said annular groove and which co-operates wtih the wedge blockstherein to limit the rotation of said tool-carrying means to apredetermined arc.

9. In combination, a mount for a dressing tool, slide means for movingsaid mount in a plane, revolving means for revolving said slide meansand mount carried thereby about an axis of rotation, suport means forsupporting said revolving means in position to revolve relative to saidaxis, said plane and said axis being disposed at right angles to eachother, and magnifying means carried by said revolving means andpositioned athwart said axis of rotation and providing a magnified viewalong said axis toward said mount, said mount being spaced along saidaxis from said magnifying means to provide space for positioning agrinding wheel being dressed Within the view along said axis andintermediate of said magnifying means and said mount an annular membercarried by said revolving means, said annular member having an annulargroove arranged around the periphery' thereof, a pair of wedge bloclgsadjustably positioned in said groove, a linger-like stop member securedto said supporting member adjacent said annular member, said linger-likestop member having a portion which projects into said annular groove andY which co-operates with the wedge blocks therein to limit the rotationof said revolving means to a predetermined arc.

References Cited in the file of this patent UNITED STATES PATENTS1,929,967 Blood Oct. 10, 1933 2,218,775 Turrettini Oct. 22, 19402,234,539 Cooke Mar. 11, 1941 2,378,401 Gardner June 19, 1945 2,395,598Weaver Feb. 26, 1946 2,608,189 Statia Aug. 20, 1952 2,642,856 CallowayJune 23, 1953 2,736,310 Baumann Feb. 28, 1956 OTHER REFERENCESIndustrial Diamond Review, volume 15, June 6, 1945, pages 132, 133.

Publication: Industrial Diamond Review, May 1951, page 113.

